Methanol-to-olefins over FeHZSM-5: Further transformation of products

• Iron oxide sites formed on the external surface of HZSM-5
• Changed weak acid and strong acid amount of HZSM-5 due to Fe modification
• Successive transformation of the products of MTO over iron oxide sites
• Weak acidity and cracking activity promote the selective formation of propylene.

The catalytic activity of FeHZSM-5 was investigated for the conversion of both methanol and mixed C3° + C4 hydrocarbons. For methanol conversion at WHSV = 1 h− 1 and 470 °C, 0.35% FeHZSM-5 showed increased selectivity for propylene and C2=–C4= olefins by 21% and 4%, respectively, compared with HZSM-5. The selectivity of propane and butylene decreased. High temperature favored the conversion of C3° + C4 mixture while the selectivity of ethene + propylene achieved a maximum at 470 °C. Improved olefins selectivity for methanol conversion was attributed to FeHZSM-5 with more weak acid but less strong acid amount and to further transformation of the products.

Figure optionsDownload as PowerPoint slide